1. Field of the Invention
The present invention relates in general to power sunroofs for automobiles and more particularly to automotive power sunroofs of a type which uses an electric motor as a power device. More specifically, the present invention is concerned with automotive power sunroofs of a type in which a lid of the sunroof pivots between a tilt-up position and a tilt-down position.
2. Description of the Prior Art
In order to clarify the task of the present invention, one conventional power sunroof will be described with reference to FIGS. 14 to 17 of the accompanying drawings.
The power sunroof shown in the drawings is of a type having a tilting mechanism powered by an electric motor (not shown). That is, due to operation of the electric motor, a lid 101 of the sunroof is pivoted between a tilt-up position as shown in FIG. 15 wherein the lid 101 is tilted up about its front end and a full-close position as shown in FIG. 16 wherein the lid 101 fully closes a sunroof opening 105 which is defined by a roof panel 109 of a motor vehicle. The lid 101 is provided around its periphery with a weather strip 103 for achieving watertight sealing of the lid 101 against the sunroof opening 105 when the lid 101 assumes the full-close position.
When the lid 101 is pivoted down from the tilt-up position to the full-close position pressing the weather strip 103 against a peripheral edge 107 of the sunroof opening 105, the weather strip 103 is largely deformed by the peripheral edge 107.
However, as is seen from FIG. 14, the large deformation of the weather strip 103 causes a lip portion thereof unsightly projected to the outside of the roof panel 109. This phenomenon tends to prevent the lid 101 from taking the proper full-close position. Furthermore, this phenomenon lowers the external appearance of the vehicle because a considerable gap "d" is produced between the weather strip 103 and the roof panel 109.
One of measures for solving this drawback is disclosed in Japanese Patent First Provisional Publication No. 59-202934. In the measure, a cam mechanism is used by which, as is seen from FIG. 17, the lid 101 is tilted down beyond the full-close position to a so-called "flap-down" position and then tilted up to the full-close position.
However, this measure has other drawbacks. First, provision of the cam mechanism increases the number of parts used and thus the sunroof becomes complicated in construction and heavy in weight. Second, due to the nature of a cam member used in the mechanism, it is very difficult to obtain a smooth and effective pivotal movement of the lid 101.